In the mobile communication system, a handover, in which a mobile station switches a connection destination from one base station to another base station due to a travel between cells or degradation of communication quality, is carried out. A handover, which can smoothly switch between communication destinations while a communication state of an application is maintained, is specifically referred to as seamless handover.
The seamless handover is defined in the eXtended Global Platform (XGP) known as a next-generation PHS (refer to Non Patent Literature 1).